Wireless carriers are required by the Federal Communications Commission (FCC) to support enhanced 911 (E911) service that enables the carrier to provide emergency personnel with an approximate location of a wireless caller that places a 911 call. Initially, under Phase I E911 requirements, wireless carriers simply had to identify the telephone number of the caller and the location of the cell site or base station through which the call was received. Under Phase II E911, wireless carriers must provide the public safety answering point (PSAP) with the longitude and latitude location of all wireless 911 callers in compliance with certain accuracy and reliability standards that differ for network-based solutions and handset-based solutions.
Using a network-based location technology, hardware and/or software on the wireless network side is used to determine locations, rather than using any special locating hardware and/or software in the mobile station itself. According to Phase II E911 requirements for network-based solutions, wireless carriers must deploy automatic location identification technologies that identify location within one hundred meters for sixty seven percent of calls and within three hundred meters for ninety five percent of calls. Using a handset-based location technology, the mobile station includes special locating hardware and/or software, which may or may not be supplemented by hardware and/or software on the network side. According to Phase II E911 requirements for handset-based solutions, wireless carriers must deploy automatic location identification technologies that identify location within fifty meters for sixty seven percent of calls and within one hundred fifty meters for ninety five percent of calls.
In addition to the FCC's E911 service requirements, wireless carriers may offer other value-added services based on locating technologies. Both to comply with the E911 requirements and to ensure that deployed locating technologies provide adequate accuracy to satisfy the purposes of such value-added services, wireless carriers need to perform tests to verify the accuracy of the locating technologies. Typically, such tests rely upon empirical measurements. For example, testing locating accuracy throughout even a relatively small geographic region may involve placing thousands of test calls from various different locations throughout the region to determine how the actual known location from which each call is placed compares with the location estimate determined and/or reported by the wireless network. Such empirical tests may also need to be repeated periodically to ensure continued accuracy in the face of changing environmental conditions, aging equipment, changes to the network infrastructure, and the like.